Semiconductor Module Cooling System

ABSTRACT

A cooling apparatus includes a discrete module and a plastic housing. The discrete module incudes a semiconductor die encapsulated by a mold compound, a plurality of leads electrically connected to the semiconductor die and protruding out of the mold compound and a first cooling plate at least partly uncovered by the mold compound. The plastic housing surrounds the periphery of the discrete module. The plastic housing includes a first singular plastic part which receives the discrete module and a second singular plastic part attached to a periphery of the first plastic part. The second plastic part has a cutout which exposes at least part of the first cooling plate and a sealing structure containing a sealing material which forms a water-tight seal around the periphery of the discrete module at a side of the discrete module with the first cooling plate.

TECHNICAL FIELD

The instant application relates to semiconductor modules, and moreparticularly to cooling systems for semiconductor modules.

BACKGROUND

Power modules with double-side cooling significantly improve the thermalperformance of the package by reducing thermal resistance, and therebyincreasing the power density of the entire system. However, powermodules with double-sided cooling present a challenge with regard tointegrating a heat-sink with the module. The design of the cooler oftenis a critical issue in achieving the highest possible performance. Forexample, the cooling fluid should be distributed in two differentchannels above and below the power modules included in the package toincrease the thermal performance of the package. Also, the entire systemmust be watertight. The heat sink should be robust, low-cost andlightweight.

Conventional double-sided module cooling technologies require additionalparts such as O-rings and bolts or screws to achieve a water-tightsystem. Conventional aluminum coolers also use thicker aluminum blocks.Still further components are typically needed to achieve a watertightheat-sink and bi-directional coolant distribution. These additionalparts increase the system weight and cost and still present a real riskof fluid leakage. Furthermore, the need for many assembly stepsincreases production cost.

SUMMARY

Embodiments described herein provide a cooling system for moldedsemiconductor modules without using bolt connections or O-rings. Thecooling system described herein has a much lower risk of fluid leakageand higher design flexibility compared to conventional power modulecooling systems, significantly reducing system cost, the number ofassembly steps and system weight.

According to an embodiment of a cooling apparatus, the cooling apparatuscomprises a plurality of discrete modules and a plastic housing. Eachmodule comprises a semiconductor die encapsulated by a mold compound, aplurality of leads electrically connected to the semiconductor die andprotruding out of the mold compound and a first cooling plate at leastpartly uncovered by the mold compound. The plastic housing surrounds theperiphery of each module to form a multi-die module. The plastic housingincludes a first singular plastic part which receives the modules and asecond singular plastic part attached to a periphery of the firstplastic part. The second plastic part has cutouts which expose the firstcooling plates and a sealing structure containing a sealing materialwhich forms a water-tight seal around the periphery of each module at aside of the modules with the first cooling plates.

According to an embodiment of a method of manufacturing a coolingapparatus, the method comprises: receiving a plurality of modules by afirst singular plastic part, each of the modules comprising asemiconductor die encapsulated by a mold compound, a plurality of leadselectrically connected to the semiconductor die and protruding out ofthe mold compound, and a first cooling plate at least partly uncoveredby the mold compound; attaching a second singular plastic part to aperiphery of the first plastic part to form a plastic housing, theplastic housing surrounding a periphery of each module to form amulti-die module, the second plastic part having cutouts which exposethe first cooling plates and a sealing structure facing a side of themodules with the first cooling plates; and filling the sealing structurewith a sealing material which forms a water-tight seal around theperiphery of each module at the side of the modules with the firstcooling plates.

According to another embodiment of a cooling apparatus, the coolingapparatus comprises a plurality of discrete modules each of whichcomprises a semiconductor die encapsulated by a mold compound, aplurality of leads electrically connected to the semiconductor die andprotruding out of the mold compound, and a first cooling plate at leastpartly uncovered by the mold compound. The cooling apparatus furthercomprises a first and second plastic housing each of which surrounds aperiphery of a different subset of the modules to form separatemulti-die modules. Each of the plastic housings comprises a firstsingular plastic part which receives the corresponding subset of modulesand a second singular plastic part attached to a periphery of the firstplastic part, the second plastic part having cutouts which expose thefirst cooling plates and a sealing structure containing a sealingmaterial which forms a water-tight seal around the periphery of eachmodule at a side of the modules with the first cooling plates. Thecooling apparatus also comprises first, second and third covers. Thefirst cover is attached to a periphery of the second plastic part of thefirst plastic housing so as to form a water-tight seal with the secondplastic part of the first plastic housing and an enclosed cavity betweenthe first cover and the second plastic part, the enclosed cavityconfigured to permit fluid flow over the first cooling plates of eachdiscrete module included in the first plastic housing. The second coveris interposed between and attached to the first and the second plastichousings. The second cover is attached to a periphery of the secondplastic part of the second plastic housing so as to form a water-tightseal with the second plastic part of the second plastic housing and anenclosed cavity between the second cover and the second plastic part,the enclosed cavity configured to permit fluid flow over the firstcooling plates of each discrete module included in the second plastichousing. The third cover is attached to a side of the second plastichousing opposite the second cover.

Those skilled in the art will recognize additional features andadvantages upon reading the following detailed description, and uponviewing the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The elements of the drawings are not necessarily to scale relative toeach other. Like reference numerals designate corresponding similarparts. The features of the various illustrated embodiments can becombined unless they exclude each other. Embodiments are depicted in thedrawings and are detailed in the description which follows,

FIG. 1 illustrates an embodiment of a plurality of discrete modules,

FIGS. 2A and 2B illustrate an embodiment of a plastic housing whichsurrounds the periphery of a plurality of discrete modules to form amulti-die module.

FIG. 3 illustrates a sectional view of the assembled multi-die modulealong the line labeled A-A′ in FIG. 2B.

FIGS. 4A and 4B illustrate an embodiment of two covers attached torespective sides of a plastic housing to form a water-tight coolingapparatus.

FIGS. 5A and 5B illustrates an embodiment of a plurality of coversattached to a plurality of plastic housings to form a water-tightcooling apparatus,

FIGS. 6A and 6B illustrates another embodiment of a plurality of coversattached to a plurality of plastic housings to form a water-tightcooling apparatus.

FIG. 7 shows a width-wise cross-sectional view of an embodiment of oneplastic housing interposed between two covers.

FIG. 8 shows a length-wise cross-sectional view of an embodiment of oneplastic housing interposed between two covers.

DETAILED DESCRIPTION

According to embodiments described herein, a cooling system for moldedsemiconductor modules is provided. Each semiconductor module includes asemiconductor die encapsulated by a mold compound, a plurality of leadselectrically connected to the semiconductor die and at least partlyuncovered by the mold compound, and a first cooling plate at leastpartly uncovered by the mold compound. The cooling system furthercomprises a plastic housing which surrounds the periphery of each moduleto form a multi-die module, The plastic housing includes a firstsingular plastic part which receives the modules and a second singularplastic part attached to a periphery of the first plastic part. Thesecond plastic part has cutouts which expose the first cooling platesand a sealing structure containing a sealing material which forms awater-tight seal around the periphery of each module at a side of themodules with the first cooling plates.

In the case of double-sided cooling, each discrete module has a secondcooling plate at a side opposite the first cooling plate and the firstplastic part has cutouts which expose the second cooling plates. Thefirst plastic part also has a sealing structure containing additionalsealing material which forms a water-tight seal around the periphery ofeach module at the side of the modules with the second cooling plates. Acover can be attached to the periphery of one or both plastic parts toform a water-tight seal with the corresponding plastic part. An enclosedcavity between each cover and the corresponding plastic part permitsfluid flow over the cooling plates of each discrete module. The coolingsystem does not require bolt connections or O-rings. As such, thecooling system has a much lower risk of fluid leakage and higher designflexibility compared to conventional power module cooling systems,significantly reducing system cost, the number of assembly steps andsystem weight.

FIG. 1 shows an embodiment of a plurality of discrete modules 100. Themodules 100 can be purchased or manufactured. In either case, eachmodule 100 comprises a semiconductor die encapsulated by a mold compound102 such as an epoxy, a plurality of leads 104 electrically connected tothe semiconductor die and at least partly uncovered by the mold compound102, and a cooling plate 106 at least partly uncovered by the moldcompound 102. The leads 104 provide the necessary electrical connectionsto the semiconductor die. The leads 104 can be of the lead-frame typewhich protrude out from the mold compound 102 of the modules 100 asshown in FIG. 1. Other types of leads 104 can be used such as the kindused in surface-mount modules, e.g. gull-wing, J-lead or flat leads.

The semiconductor dies) included in each discrete module 100 andconnected to the corresponding leads 104 can be any type ofsemiconductor die requiring liquid cooling during operation such as anIGBT (insulated gate bipolar transistor) die, power MOSFET (metal oxidesemiconductor field effect transistor) die, JFET (junction field effecttransistor) die, GaN die, SiC die, thyristor die, power diode die, etc.More than one semiconductor die can be included in some or all of themodules 100, as well as passive components. The semiconductor dies canform any type of desired circuit such as a half-bridge, full-bridge or3-phase circuit, etc.

Each discrete module 100 can have a single cooling plate 106 at one sideof the module 100, or a pair of spaced apart cooling plates 106 atopposing sides of the module 100 with the corresponding semiconductordie interposed between the pair of cooling plates 106 (the bottom modulecooling plates are out of view in FIG. 1). In either case, the modulecooling plates 106 remain at least partly uncovered by the mold compound102 of the corresponding module 100. The cooling plates 106 can havesurface structures such as pins, fins or an intentionally roughenedsurface at a side of the cooling plates for increasing the turbulence offluid flowing over the cooling plates.

In FIGS. 2A and 2B, a plastic housing 200 is formed which surrounds theperiphery of each module 102 to form a multi-die module 202. FIG. 2Ashows the plastic housing 200 prior to assembly, and FIG. 2B shows theplastic housing 200 after assembly.

The plastic housing 200 includes first and second singular (i.e.individual or discrete) plastic parts 204, 206. The plastic parts 204,206 can be formed using any standard process such as injection molding,3-D printing, etc. In general, the first singular plastic part 204receives the modules 102. The second singular plastic part 206 isattached to the periphery 208 of the first plastic part 204 and hascutouts 210 which expose the first cooling plates 106 of the modules102. The second plastic part 206 also has a sealing structure 212 forcontaining a sealing material which forms a water-tight seal around theperiphery 212 of each module 102 at a side of the modules 102 with thefirst cooling plates 106 after assembly.

In the case of a double-side cooling configuration as shown in FIGS. 2Aand 2B, each discrete module 102 has a second cooling plate (out ofview) at the side opposite the first cooling plate 106. According tothis embodiment, the first plastic part 204 also has cutouts or windows214 which expose the second cooling plates and a sealing structure 216for containing sealing material which forms a water-tight seal aroundthe periphery 212 of each module 102 at the side of the modules with thesecond cooling plates.

Both plastic parts 204, 206 have one or more openings 218 along theirrespective lengths for injecting the sealing material into the sealingstructure 212, 216 of the corresponding plastic part 204, 206. Theplastic parts 204, 206 can also include one or more openings 220 at oneor both ends of the plastic parts 204, 206 for allowing fluid flow fromone side of the housing 200 to the other side after covers are attachedto both sides of the assembled plastic housing 200. The first plasticpart 204 can be attached to the second plastic part 206 using anystandard plastic attach process such as plastic welding, laser welding,heat sealing, gluing, etc.

FIG. 3 shows a sectional view of the assembled multi-die module 202along the line labeled A-A′ in FIG. 2B. The first plastic part 204 hasrecessed regions 300 for receiving the discrete modules 102. Thediscrete modules 102 are seated in the respective recessed regions 300.Each discrete module 102 has a pair of spaced apart cooling plates 106according to this embodiment, as previously described herein. Therecessed regions 300 have cutouts or windows 302 so that the lowercooling plates 106 remain at least partly uncovered by the plastichousing 200 after assembly. The plastic housing 200 can have openpassageways 220 at opposing ends of the housing 200 as shown in FIGS. 2Aand 2B, to permit a fluid to flow in direct contact with the coolingplates 106 at both sides of the discrete modules 102.

The leads 104 of each discrete module 104 remain at least partlyuncovered by the plastic housing 200. In the case of lead-frame type orsimilar leads, the leads 104 of each discrete module 102 protrude out ofthe plastic housing 200 as shown in FIGS. 2B and 3. A different modulelead configuration is possible with other types of module leads such assurface-mount leads. In each case, electrical connections can be made tothe discrete modules 102 and the discrete modules 102 can be directlycooled at the exposed side of the cooling plates 106.

Further according to the double-sided cooling embodiment shown in FIG.3, the first and second plastic parts 204, 206 of the plastic housing200 both have respective sealing structures 216, 212. Each sealingstructure 216, 212 comprises a groove or passage 304 formed in thecorresponding plastic part 204, 206 which surrounds the periphery ofeach module 102 at the side of the module 102 with a cooling plate 106.Each groove 304 is configured to be filled with a sealing material thatforms a water-tight seal around the periphery of the correspondingmodule 102. The (upper and lower) cooling plates 106 remain exposed dueto the cutouts or windows 302 formed in the first and second plasticparts 204, 206 of the plastic housing 200. A part 306 of each plasticpart 204, 206 disposed interiorly from the grooves 304 contacts the sideof the modules 102 with a cooling plate 106 and forms a dam-likestructure which prevents sealing material from leaking onto the coolingplates 106. The sealing material can be injected into the grooves 304through one or more openings 220 formed in the first and second plasticparts 204, 206 of the housing 200. The plastic housing parts 204, 206can include additional openings 308 for ventilation.

In FIGS. 4A and 4B, respective covers 400, 402 are attached to bothsides of the plastic housing 200 to form a cooling apparatus 404. FIG.4A shows the covers 400, 402 and plastic housing 200 prior to assembly,and FIG. 4B shows the cooling apparatus 404 after assembly.

A first cover 400 is attached to the periphery of the second plasticpart 406 and forms a water-tight seal with the second plastic part 206.An enclosed cavity 406 is formed between the first cover 400 and thesecond plastic part 206. The enclosed cavity 406 is configured to permitfluid flow over the first cooling plates 106 of each discrete module102. The second cover 402 is attached to a periphery of the firstplastic part 204 and forms a water-tight seal with the first plasticpart 204. An enclosed cavity 406 between the second cover 402 and thefirst plastic part 204 is configured to permit fluid flow over thesecond cooling plates 106 of each discrete module 102.

On or both covers 400, 402 have at least one port 410 for permittingfluid flow into and out of the cooling apparatus 404, The fluid flowswithin the enclosed cavities 406, 408 formed between the respectivecovers 400, 402 and plastic parts 204, 206 of the plastic housing 200,traversing over the cooling plates 106 of the discrete modules 102. Eachplastic part 204, 206 of the plastic housing 200 can have one or moreopenings 220 at one or both ends of the plastic part 204, 206 forallowing fluid flow from one side of the plastic housing 200 to theother side after the covers 400, 402 are attached to both sides of theassembled plastic housing 200. In one embodiment, the covers 400, 402are made of plastic and attached to the periphery of the respectiveplastic parts 204, 206 of the plastic housing 200 by any standardplastic attach process such as plastic welding, laser welding, heatsealing, gluing, etc.

FIGS. 5A and 5B illustrate another embodiment of a cooling apparatus500. FIG. 5A shows an exploded view of the cooling apparatus 500, andFIG. 5B shows an assembled view of the cooling apparatus 500. Accordingto this embodiment, the cooling apparatus 500 includes a plurality ofdiscrete modules, two plastic housings 502, 504 and three covers 506,508, 510, Each of the discrete modules includes a semiconductor dieencapsulated by a mold compound, a plurality of leads electricallyconnected to the semiconductor die and protruding out of the moldcompound, and a first cooling plate 106 at least partly uncovered by themold compound e.g. as previously described herein in connection withFIG. 1. Each of the plastic housings 502, 504 surrounds a periphery of adifferent subset of the modules to form separate multi-die modules. Eachplastic housing 502, 504 includes a first singular plastic part whichreceives the corresponding subset of modules and a second singularplastic part attached to a periphery of the first plastic part, thesecond plastic part having cutouts which expose the first cooling plates106 and a sealing structure containing a sealing material which forms awater-tight seal around the periphery of each module at a side of themodules with the first cooling plates 106 e.g. as previously describedherein in connection with FIGS. 2A, 2B and 3.

The first cover 506 is attached to the periphery of the second plasticpart of the first plastic housing 502 so as to form a water-tight sealwith the second plastic part of the first plastic housing 502 and anenclosed cavity 512 between the first cover 506 and the second plasticpart e.g. as previously described herein in connection with FIGS. 4A and4B. The enclosed cavity 512 between the first cover 506 and the secondplastic part of the first plastic housing 502 is configured to permitfluid flow over the first cooling plates 106 of each discrete moduleincluded in the first plastic housing 502.

The second cover 508 is interposed between and attached to the first andthe second plastic housings 502, 504. The second cover 508 is attachedto the periphery of the second plastic part of the second plastichousing 504 so as to form a water-tight seal with the second plasticpart of the second plastic housing 504 and an enclosed cavity 514between the second cover and the second plastic part e.g. as previouslydescribed herein in connection with FIGS. 4A and 4B. The enclosed cavity514 between the second cover 508 and the second plastic part of thesecond plastic housing 504 is configured to permit fluid flow over thefirst cooling plates 106 of each discrete module included in the secondplastic housing 504. The third cover 510 is attached to the side of thesecond plastic housing 504 opposite the second cover 508. In oneembodiment, the covers 506, 508, 510 are each made of plastic andattached to the periphery of the respective plastic parts of the plastichousings 502, 504 by any standard plastic attach process such as plasticwelding, laser welding, heat sealing, gluing, over-molding, etc.

The second cover 508 is attached to the periphery of the first plasticpart of the first plastic housing 502 at a side of the first plastichousing 502 facing away from the first cover 506 so as to form awater-tight seal with the first plastic part of the first plastichousing 502 and an enclosed cavity (out of view) between the secondcover and the first plastic part e.g. as previously described herein inconnection with FIGS. 4A and 4B. The enclosed cavity between the secondcover 508 and the first plastic part of the first plastic housing 502 isconfigured to permit fluid flow over second cooling plates 106 of eachdiscrete module included in the first plastic housing 502 which aredisposed at a side of the modules facing away from the first cover 506.

The third cover 510 is attached to the periphery of the first plasticpart of the second plastic housing 504 at a side of the second plastichousing facing away from the second cover 508 so as to form awater-tight seal with the first plastic part of the second plastichousing 508 and an enclosed cavity (out of view) between the third cover510 and the first plastic part. The enclosed cavity between the thirdcover and the first plastic part of the second plastic housing 508 isconfigured to permit fluid flow over second cooling plates 106 of eachdiscrete module included in the second plastic housing 504 which aredisposed at a side of the modules facing away from the second cover 508.

According to the embodiment shown in FIGS. 5A and 5B, the first cover506 has an inlet port 516 for receiving (cooled) fluid into the coolingapparatus 500 and an outlet port 518 for removing (heated) fluid fromthe cooling apparatus 500. According to this embodiment, the secondcover 508 has one or more openings 520 configured to permit fluid flowbetween the first and the second plastic housings 502, 504 and allow fordouble-side cooling of all modules included in both plastic housings502, 504. The third cover 510 does not have any ports according to thisembodiment. Alternatively, the third cover 510 can have both inlet andoutlet ports or the first cover 506 can have one port and the thirdcover 510 can have the other port. In each case, the openings 520 in thesecond cover 508 are aligned with corresponding openings 522 in thefirst and second plastic housings 502, 504 to permit fluid flow acrossthe cooling plates 106 at opposing sides of the modules included in bothplastic housings 502, 504.

FIGS. 6A and 6B illustrate yet another embodiment of a cooling apparatus600. FIG. 6A shows an exploded view of the cooling apparatus 600, andFIG. 6B shows an assembled view of the cooling apparatus 600. Theembodiment shown in FIGS. 6A and 6B is similar to the embodiment shownin FIGS. 5A and 5B. The cooling system 500 shown in FIGS. 5A and 5B isextended to at least three plastic housings 502, 504, 602 and at leastfour covers, 506, 508, 510, 604. The third plastic housing 602 surroundsthe periphery of a different subset of the modules than the first andthe second plastic housings 502, 504 to form an additional multi-diemodule as previously described herein. The third cover 510 is attachedto the periphery of the first plastic part of the second plastic housing504 at a side of the second plastic housing 504 facing away from thesecond cover 508 so as to form a water-tight seal with the first plasticpart of the second plastic housing 504 and an enclosed cavity 606between the third cover 510 and the first plastic part. The enclosedcavity 606 between the third cover 510 and the first plastic part of thesecond plastic housing 504 is configured to permit fluid flow oversecond cooling plates 106 of each discrete module included in the secondplastic housing 504 which face away from the second cover 508.

The fourth cover 604 is attached to the periphery of the first plasticpart of the third plastic housing 602 at a side of the third plastichousing 602 facing away from the third cover 510 so as to form awater-tight seal with the first plastic part of the third plastichousing 602 and an enclosed cavity (out of view) between the fourthcover 604 and the first plastic part. The enclosed cavity between thefourth cover 604 and the first plastic part of the third plastic housing602 is configured to permit fluid flow over second cooling plates 106 ofeach discrete module included in the third plastic housing 602 whichface away from the third cover 510.

The cooling apparatus covers can include surface features which enhancethe flow of fluid with the corresponding cooling apparatus.

FIG. 7 shows a width-wise cross-sectional view of an embodiment of aplastic housing 700 of the kind previously described herein having awater-tight seal between two covers 702, 704. Fluid enters an inlet port706 in one cover 702. The other cover 704 can include a slanted orangled surface feature 708 for re-directing the fluid toward an openingor passage 710 in the corresponding end of the plastic housing 700. Thisfeature allows fluid entering the inlet port 706 in the first cover 702to more easily flow unimpeded to plastic housings above and below theplastic housing 700 shown in FIG. 7. The fluid flow path is indicated bydashed lines in FIG. 7.

FIG. 8 shows a length-wise cross-sectional view of an embodiment of aplastic housing 800 of the kind previously described herein having awater-tight seal between two covers 802, 804. Fluid enters one end ofthe plastic housing 800 from the top cover 802 in the left-hand side ofFIG. 8. This end of the plastic housing 800 has an opening 806 whichallows the fluid to split and flow in a sealed cavity 808 between thetop cover 802 and the plastic housing 800 and a sealed cavity 810between the bottom cover 804 and the plastic housing 800. At theopposite end of the plastic cavity 800, the fluid flow merges in asecond opening 812 in the plastic housing 800 and is directed downwardthrough an opening 814 in the bottom cover 804 in the right-hand side ofFIG. 8. The fluid flow path is indicated by dashed lines in FIG. 8.

Spatially relative terms such as “under”, “below”, “lower”, “over”,“upper” and the like, are used for ease of description to explain thepositioning of one element relative to a second element. These terms areintended to encompass different orientations of the device in additionto different orientations than those depicted in the figures. Further,terms such as “first”, “second”, and the like, are also used to describevarious elements, regions, sections, etc. and are also not intended tobe limiting. Like terms refer to like elements throughout thedescription.

As used herein, the terms “having”, “containing”, “including”,“comprising” and the like are open-ended terms that indicate thepresence of stated elements or features, but do not preclude additionalelements or features. The articles “a”, “an” and “the” are intended toinclude the plural as well as the singular, unless the context clearlyindicates otherwise.

With the above range of variations and applications in mind, it shouldbe understood that the present invention is not limited by the foregoingdescription, nor is it limited by the accompanying drawings. Instead,the present invention is limited only by the following claims and theirlegal equivalents.

What is claimed is:
 1. A cooling apparatus, comprising: a discretemodule comprising: a semiconductor die encapsulated by a mold compound;a plurality of leads electrically connected to the semiconductor die andprotruding out of the mold compound; and a first cooling plate at leastpartly uncovered by the mold compound; and a plastic housing surroundinga periphery of the discrete module, the plastic housing comprising: afirst singular plastic part which receives the discrete module: and asecond singular plastic part attached to a periphery of the firstplastic part, the second plastic part having a cutout which exposes atleast part of the first cooling plate and a sealing structure containinga sealing material which forms a water-tight seal around the peripheryof the discrete module at a side of the discrete module with the firstcooling plate.
 2. The cooling apparatus of claim 1, wherein the sealingstructure of the second plastic part comprises a groove formed in thesecond plastic part which surrounds the periphery of the discrete moduleat the side of the discrete with the first cooling plate, and whereinthe sealing material fills the groove.
 3. The cooling apparatus of claim2, wherein a part of the second plastic part disposed interiorly fromthe groove contacts the side of the discrete with the first coolingplate to prevent the sealing material from leaking onto the firstcooling plate.
 4. The cooling apparatus of claim 1, further comprising:a first cover attached to a periphery of the second plastic part andforming a water-tight seal with the second plastic part; and an enclosedcavity between the first cover and the second plastic part configured topermit fluid flow over the first cooling plate of the discrete module.5. The cooling apparatus of claim 1, wherein the discrete module has asecond cooling plate at a side opposite the first cooling plate, andwherein the first plastic part has a cutout which exposes at least partof the second cooling plate and a sealing structure containingadditional sealing material which forms a water-tight seal around theperiphery of the discrete module at the side of the discrete module withthe second cooling plate.
 6. The cooling apparatus of claim 5, whereinthe sealing structure of the first plastic part comprises a grooveformed in the first plastic part which surrounds the periphery of thediscrete module at the side of the discrete module with the secondcooling plate, and wherein the additional sealing material fills thegroove in the first plastic part.
 7. The cooling apparatus of claim 6,wherein a part of the first plastic part disposed interiorly from thegroove contacts the side of the discrete module with the second coolingplate to prevent the additional sealing material from leaking onto thesecond cooling plate. The cooling apparatus of claim 5, furthercomprising: a second cover attached to a periphery of the first plasticpart and forming a water-tight seal with the first plastic part; and anenclosed cavity between the second cover and the first plastic partconfigured to permit fluid flow over the second cooling plate of thediscrete module.
 9. The cooling apparatus of claim 5, wherein the firstsingular plastic part has one or more openings along the length of thefirst singular plastic part configured to inject the sealing materialinto the sealing structure of the first singular plastic part.
 10. Thecooling apparatus of claim 1, wherein the mold compound is an epoxy. 11.The cooling apparatus of claim 1, wherein the leads are formed from alead-frame.
 12. The cooling apparatus of claim 1, wherein the leads aregull-wing, J-lead or flat leads.
 13. The cooling apparatus of claim 1,wherein the semiconductor die is an IGBT die, a power MOSFET die, a JFETdie, a GaN die, a SiC die, a thyristor die, or a power diode die. 14.The cooling apparatus of claim 1, wherein a plurality of semiconductordies is included in the discrete module.
 15. The cooling apparatus ofclaim 1, wherein the semiconductor die forms part of a half-bridgecircuit, a full-bridge circuit or a 3-phase circuit.
 16. The coolingapparatus of claim 1, wherein the cooling plate has surface structuresconfigured to increase the turbulence of fluid flowing over the coolingplate.
 17. The cooling apparatus of claim 16, wherein the surfacestructures are pins, fins or an intentionally roughened surface.
 18. Thecooling apparatus of claim 1, wherein the first and the second singularplastic parts include one or more openings at one or both ends of thefirst and the second singular plastic parts configured to allow fluidflow from one side of the plastic housing to an opposite side of theplastic housing.
 19. The cooling apparatus of claim 1, wherein thediscrete module is seated in a recessed region of the first plasticpart.
 20. The cooling apparatus of claim 1, wherein the second singularplastic part has one or more openings along the length of the secondsingular plastic part configured to inject the sealing material into thesealing structure of the second singular plastic part.